The present invention relates to a process for recovering fine coal particles from slurries of finely divided coal.
Slurries consisting only of water and finely divided coal of the order of microns in particle size are transported generally through relatively short pipelines under some process conditions. After such a slurry has been transported, there is the need to dewater and dry the slurry for the recovery of the coal. When the slurry of finely divided coal is dewatered with a filter, the filter will become clogged up, resulting in a greatly reduced dewatering efficiency. The slurry has other problems in that it requires a long period of time for drying and is likely to release fines as dust. Although it appears useful to mix fuel oil or like binder directly with the slurry of fine coal particles to granulate the particles, it is difficult to adhere the binder to the coal particles, which are extremely minute, and therefore, to granulate the particles. Furthermore, it takes a great deal of time to obtain sufficiently large granules or pellets, while there is the necessity of using a large amount of binder since finely divided coal has a large surface area per unit weight. Consequently the method described fails to recover fine coal particles efficiently.